The present invention relates to a washer used for tightening and loosening threaded connectors.
Washers are used for tightening and loosening threaded connectors, for example flanges. During tightening and loosening a circumferential bolt load is critical for keeping the flanges tight. It is difficult to obtain a desired bolt load at all times simply because there is no tool that can be set to a given bolt load and will ultimately achieve that bolt load. The reason is that during the process of tightening there are two many variables.
The two most popular bolting systems for tightening and loosening threaded connectors use torque or tension. When the torque is used for tightening or loosening, the torque has unknown friction, so that with the same torque, different bolt loads are obtained even on the same flange. When the tension is used for tightening or loosening threaded connectors, the tension has an unknown bolt relaxation, so that with the same identical pulling force of the bolt, different final bolt loads are obtained even on the same flange. This is because the nut is usually tightened by hand while the bolt is elongated by pull, and thus the bolt relaxation, which is to tighten the nut, depends on cleanness of threads or amount of debris underneath the nut, the smoothness of the nut and the joint face, perpendicularity joint face relative to the bolt axis, etc.